Alarm tag

Abstract

An alarm device, comprising a so-called alarm tag consisting of two parts arranged so as to be placeable each on one side of an article, for example an article of clothing, of fur or other article, where a needle is provided to extend from one part through the article to the second part, which alarm tag comprises devices for receiving a magnetic alternating field emitted to the alarm tag. According to the invention, the alarm tag (1) comprises devices (8,9,11,12) capable to emit an acoustic signal when the parts (2,3) of the alarm tag (1) move away from each other when the alarm tag (1) is put in a first, active, state and not to emit an acoustic signal when the parts (2,3) of the alarm tag (1) move away from each other when the alarm tag (1) is put in a second, inactive, state.

We claim: 
     
       1. An alarm device, comprising a so-called alarm tag consisting of two parts arranged so as to be placeable each on one side of an article, for example an article of clothing, of fur or other article, where a needle is provided to extend from one part through the article to the second part, which alarm tag comprises means for receiving a magnetic alternating field emitted to the alarm tag, which tag (1) comprises devices (8-12) capable to emit an acoustic signal when the parts (2,3) of the alarm tag (1) move away from each other when the alarm tag (1) is in a first, active, state and not to emit an acoustic signal when the parts (2,3) of the alarm tag (1) move away from each other when the alarm tag (1) is put in a second, inactive, state, said devices (8-12) comprising a switch (8), a coil (9), a detector circuit (10), a control circuit (11) and a loudspeaker (12), which devices are attached in the alarm tag (1) and are in operable communication with each other, where said switch (8) is capable when the parts of the alarm tag (1) move away from each other to open an electric circuit, and the control circuit (11) is capable to emit a signal to the loudspeaker (12) when the alarm tag (1) is put in said active state, characterized in that said switch (8) comprises one or several needles (6,7), which needle or needles (6,7) in closed position of the alarm tag are arranged to form a closed electric circuit between the two parts (2,3) of the alarm tag, where said electric circuit is opened when said needle or needles (6,7) are moved away from one (2,3) or the other (3,2) part of the alarm tag, and in that one of said devices for putting the alarm tag in an inactive state comprises a receiving circuit comprising said coil (9) and a first detector circuit (10), where said receiving circuit is tuned to a magnetic alternating field of a first predetermined frequency (F1), and that the detector circuit (10) is capable to emit a signal to the control circuit (11) to put the alarm tag in the inactive state when an alternating field of said first predetermined frequency (F1) is detected. 
     
     
       2. An alarm device as defined in claim 1, characterized in that one or several needles (6,7) are attached in a first part (3) of the two parts (2,3) of the alarm tag (1), and that the needle or needles (6,7) is/are arranged to co-operate with electric conductors (16,17) in a second one (2) of the two parts of the alarm tag (1). 
     
     
       3. An alarm device as defined in claim 1, characterized in that said devices for receiving a magnetic alternating field emitted to the alarm tag comprise a receiving circuit comprising a coil (31) and a second detector circuit (32) tuned to a second predetermined frequency (F2), and that the second detector circuit (32) is capable upon detection of an alternating field of said second frequency (F2) to emit a signal to the control circuit (11), which is capable thereby to emit a signal to the loudspeaker (12). 
     
     
       4. An alarm device as defined in claim 1, characterized in that said acoustic signal has a frequency within the audible range. 
     
     
       5. An alarm device as defined in claim 1, characterized in that said acoustic signal has a frequency outside the audible range, preferably a high frequency. 
     
     
       6. An alarm device as defined in claim 5, characterized in that it comprises a sound-sensitive device (34;35), for example a microphone, tuned to the frequency of the acoustic signal, and that the sound-sensitive device (34;35) is connected to a drive circuit (38, 39) capable to drive alarm devices, such as loudspeakers (40) and/or lamps (41;43) when the sound-sensitive device (34;35) has received sound of the frequency of the acoustic signal.